B. melitensis rough strain B115 is protective against heterologous Brucella spp. infections

• Published in: Vaccine 2011-03, Vol.29 (14), p.2523-2529
• Main Authors: Adone, Rosanna, Francia, Massimiliano, Pistoia, Claudia, Pesciaroli, Michele, Pasquali, Paolo
• Format: Article
• Language: English
• Subjects: Abortion; Allergy and Immunology; Animal; Animals; Antibiotics; antibodies; Antibodies, Bacterial - blood; Applied microbiology; Bacteria; Bacterial diseases; Bacterial Load; Bacterial Vaccines - immunology; Bacteriology; Biological and medical sciences; Brucella; Brucella abortus - immunology; Brucella melitensis - immunology; Brucella suis - immunology; Brucellosis; Brucellosis - immunology; Brucellosis - prevention & control; Cattle; cell-mediated immunity; Confidence intervals; Experiments; Female; Fundamental and applied biological sciences. Psychology; Genes; hosts; Human bacterial diseases; humans; Infections; Infectious diseases; Interferon-gamma - secretion; Laboratories; Livestock; Medical sciences; Mice; Microbiology; Miscellaneous; monitoring; Ovis; phenotype; protective effect; Sheep; Spleen; Spleen - microbiology; vaccination; Vaccine; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); virulence; zoonoses
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2011.01.072

Abstract Brucellosis is one of the most serious zoonoses all over the world, with B. melitensis , B. abortus and B. suis being the most pathogenic species for humans. Vaccination of domesticated livestock still represents the most efficient way to prevent human infection. However, the available Brucella vaccines retain an important residual virulence and induce antibodies interfering with surveillance programs. Moreover, each vaccine shows different protective effects versus different Brucella species and different animal hosts. Nowadays, while B. melitensis and B. suis infections in cattle are emerging as a significant problem, there are no available vaccines to overcome such issue. B. melitensis strain B115, a natural, attenuated rough strain in our previous studies proved to be highly protective against B. melitensis and B. ovis infections in mice, without inducing interfering antibodies. In this study, we tested the efficiency of B115 as vaccine against B. abortus and B. suis . Vaccination of mice with 108 CFU/mouse of B. melitensis B115 conferred a satisfactory protection against B. abortus 2308. On the contrary, mice vaccinated once with 108 or 109 CFU/mouse of B115 were weakly protected against B. suis infection. Conversely, when mice were vaccinated twice with 109 CFU B115/mouse, the protective activity significantly increased. Unlike its rough phenotype, B115 showed an adequate persistence in mice accompanied to a solid humoral and cell-mediated immunity. All together, these findings suggest the potential usefulness of B115 to control brucellosis in animal hosts due to heterologous challenges.